Look up "zirconium" in a web search engine or on eBay and you'll find thousands upon thousands of references, every single one of them to cubic zirconia jewelry. CZ, as it's known, is zirconium oxide, a hard, clear, diamond-like crystal that can be cut and polished to look a whole lot like a real diamond. Personally, I don't find that real diamonds look much, if any, better than CZ, and the notion of spending $10,000 for a diamond the same size as a $1 cubic zirconia strikes me as a bit nutty. For that kind of money you should at least get some color.

I suspect that once large gem-quality diamonds are routinely being synthesized (just a few years from now by the look of it) diamond may finally start to loose its position as the king of gems. That position was just made up by DeBeers anyway, and it's a fragile one given diamond's inherent boringness as a gemstone.

Back to zirconium, the metallic form is of course nothing like its oxide. As a metal zirconium is very corrosion resistant and is used in chemical processing equipment. But its most important use is as a cladding for nuclear fuel rods, because it has a very low neutron capture cross section (i.e. it's relatively transparent to neutrons). Since neutrons are what make a fission reactor run, it's important for the cladding not to absorb them.

Small lump 99.6%.
Kindly donated by David Franco, who sent many elements after seeing the slashdot discussion.Source:David FrancoContributor:David FrancoAcquired:17 May, 2002Price: DonatedSize: 0.2"Purity: 99.6%

Gem cut Zirconium oxide (cubic).
These beautiful 10mm brilliant cut CZ were purchased from http://www.pehnec.com in April 2002. Everyone who sees them agrees they are spectacular, especially when you consider the same size diamond would cost 10,000 times more and not look much better, if any.Source:Pehnec GemsContributor:Theodore GrayAcquired:17 April, 2002Price: $60/50 stonesSize: 0.39"Purity: 74%

Slice of Historical Sample.
We are very honored to have received a slice cut from one of the first batches of pure zirconium metal ever to have been isolated. Randall Fullman donated this sample, and has this story about it:

"My grandfather, Martin Farlee, was an engineer who worked on the process to refine this metal at the US Bureau of Mines, Albany Research Center. Due to the flammable nature of the metal and the need for high purity for the nuclear industry, the process developed involved refining it in a vacuum using induction heating. I wished I could have gotten photos of the crucibles and induction equipment. In the same chamber in which it was refined, it was poured to make ingots for the tests. This sample is from these tests."
"As an industrial metal, it is not traded as a precious metal such as gold, silver, platinum, etc. However about 30 years ago it was more valuable than platinum. "
"The metal properties that are of interest are its high strength, and the fact that it is transparent to radiation. The main use for the metal is in fuel rods in nuclear reactors. It holds the fuel pellets while not interfering with the reaction by absorbing radiation."
"Due to the use of the metal in the nuclear industries, the refining process came under the gun of the nuclear regulatory commission. Even though the metal is not radioactive, it is refined from sand from Australia. A survey of the tailings of the sand found a background radiation level very much like the level found in most red bricks used in buildings. As such it was declared low level radioactive waste, just the same as many old government buildings. This has created much grief for Wah Chang (a major refiner of zirconium), just as it has for many demolition companies trying to dispose of old bricks."

On the subject of why he's willing to send us a piece of this sample, Randall reports:
"Due to the shape of the sample, and the fact I had used it to pound nails in a pinch, taking a small slab off the bottom is not a problem. As promised, I got a sample cut for you after I found someone with a saw with liquid cooling."

Analysis by x-ray fluorescence spectroscopy at the Center for Microanalysis of Materials, University of Illinois (partially supported by the U.S. Department of Energy under grant DEFG02-91-ER45439) showed no contamination within the detection limits of the machine, at worst about 100ppm. Zirconium usually occurs together with hafnium and the two are very hard to separate, so for this sample to have no hafnium whatsoever is remarkable, and indicates that they worked really hard to purify it. This in turn indicates that it was intended for nuclear applications where such purity is a necessity.

Fake Emerald.
This is a fake (cubic zirconia based) emerald from http://www.pehnec.com. We once thought the color was from yttrium, but now I doubt that, so it's been moved under zirconium because that's the one thing I do believe about it.Source:Pehnec GemsContributor:Ed Pegg JrAcquired:15 July, 2002Text Updated:7 April, 2009Price: $10Size: 0.4"Purity: 74%

Tiny cylinder.
Ed bought half a dozen different tiny metal cylinders from David Franco, intending to make some kind of puzzle out of them (Ed's a puzzle person). But they turned out to be too irregular, so he donated them to the table. Source:David FrancoContributor:Ed Pegg JrAcquired:19 August, 2002Text Updated:11 August, 2007Price: DonatedSize: 0.2"Purity: 99.6%

Old photographic flash bulb.
Back in the dark ages, cameras used one-time-only flash bulbs that ignited a fine wire inside a glass bulb. Some or all of them used zirconium for the wire, presumably because it burned with a particularly good light. There's a bulb similar to this one under rhenium too, because it contains an igniter wire made of that metal. I don't know if this one uses a rhenium igniter or not, but it's clearly labeled as containing zirconium wire.
Reports Tryggvi:

The woolly stuff in GE flashbulbs is zirconium. (I.e. , the stuff that burns and makes the light. The bulbs are also filled with a few atmospheres of oxygen). The flashbulbs in the cubes that were used on some Kodak Instamatics were not triggered electrically (with rhenium wire), but with a percussive pyrotechnic mix inside a little metallic tube that stuck out of the bulb.

Tungsten/zirconium alloy screw plug.
Neil Lipson, the source of most of my tungsten and molybdenum, sent me this little plug in exchange for me analyzing what it's made of. He was hoping there might be iridium in it, but instead analysis by x-ray fluorescence spectroscopy at the Center for Microanalysis of Materials, University of Illinois (partially supported by the U.S. Department of Energy under grant DEFG02-91-ER45439) indicates that it's a strange mixture of primarily tungsten (62%) and zirconium (30%), with the remainder being iron and nickel.
I looked around on the web and could find no references to tungsten-zirconium alloy, but that's no proof that such a thing isn't used in specialized applications. I would guess high temperature, corrosive environments, perhaps a chemical reaction chamber that operates at high pressures and temperatures.Source:Neil LipsonContributor:Neil LipsonAcquired:18 December, 2002Price: DonatedSize: 0.75"Purity: 30%

Sample from the RGB Set.
The Red Green and Blue company in England sells a very nice element collection in several versions. Max Whitby, the director of the company, very kindly donated a complete set to the periodic table table.

Sample from the Everest Set.
Up until the early 1990's a company in Russia sold a periodic table collection with element samples. At some point their American distributor sold off the remaining stock to a man who is now selling them on eBay. The samples (except gases) weigh about 0.25 grams each, and the whole set comes in a very nice wooden box with a printed periodic table in the lid.

Wah Chang tag, hexagonal.
Wah Chang is a major refiner of niobium, zirconium, and other specialized metals. For a long time they had these little zirconium tags which they would send you, if you were contemplating using zirconium in some industrial application. They idea was you could hang it in whatever vat of horrible chemicals you were interested in processing, and find out if it could stand up to them. If it came out OK, maybe you would place an order for a ton of zirconium.
Unfortunately, they don't have them anymore! And even if they did, they wouldn't give you one just for asking, unless they really thought you might be a potential customer, not just a mooching element collector. So I had to get mine off eBay for really rather more money than it should have cost.
It's amusing to note that while it's stamped "corrosion resistant" right on the tag, the tag is in fact quite visibly corroded, or at least discolored from tarnishing. Or, it might be that it was intentionally anodized, as they are said to have done with some tokens of this sort (according to Sheryl in the marketing department).Source:eBay seller heruurContributor:Theodore GrayAcquired:3 June, 2003Price: $27Size: 1"Purity: 99.9%

Wah Chang tag, round.
This is an older, much shinier version of a zirconium tag (see previous sample for more details). According to Sheryl of the marketing department, this token was not intended for corrosion testing, but was rather just a trinket to give to people to remind them that Wah Chang supplies zirconium. She claimed that about the hexagonal one too, and she should know, but I'm not 100% convinced since the hexagonal one has a hole where you could hang it in a vat for testing purposes. This one has no hole, so it would not be suitable for testing purposes.Source:eBay seller mebiggerContributor:Theodore GrayAcquired:20 June, 2003Price: $2Size: 1"Purity: 99.9%

Tongue stud.
"Body jewelry" is a term that means jewelry meant to go through rather than simply on the body. This one is designed to go through the tongue, for example.
Niobium and titanium are commonly used for this type of jewelry, but this zirconium one is more unusual. These metals are highly corrosion resistant, which is good because the body is corrosive. Tantalum would be another obvious choice, but I haven't seen it used, probably because it's more expensive and doesn't offer any obvious advantages. Source:eBay seller perkins55Contributor:Theodore GrayAcquired:28 November, 2003Text Updated:11 March, 2007Price: $4Size: 1"Purity: 99%Sample Group:Medical

Zirconium butter nodules.
Everyone who sees these thinks they are soft, but nothing could be further from the truth. Zirconium is a very hard metal, but for some reason the silky smooth texture makes them seem soft. We believe these are hot-wire-decomposition nodules, old stock from Russia, and very pure.Source:Max Whitby of RGBContributor:Theodore GrayAcquired:16 December, 2003Price: DonatedSize: 1.25"Purity: 99.9%

Nuclear fuel rod tubes.
The seller supplied the following interesting description of these tubes:

The zirconium tubes are the ends of a long piece of tubing lathed into shorter lengths for the purpose of placing pellets of U238 for reactor function. I am acquainted with a machinist who works at a company that makes the special length reactor tubes. These short pieces of zirconium tubes are the left over pieces of the long tube after it is cut up in the special usable lengths. The purity of the zirconium is around 98.5% the other % is chrome, some iron, and ? Anyway, it is neat metal when used for certain experiments; When touching a revolving grind stone, it makes a shower of bright white sparks, the lathe turnings burn bright in air, try it in pure oxygen and better look at it through dark glasses! File some fine powder and mix it with potassium chlorate and if you light it with a fuse, it blows with 75% power of TNT! Even lighting the powder will make a blinding POOF! If powdered zirconium is wet, it will still burn with tremendous energy. The powder zirconium must be stored completely under water to be safely kept.
Zirconium is used in nuclear industry because it resists corrosion like no other metal and it is tough metal.
Larry

Pellets.
These look like "green" pressed pellets meant to be arc-melted or sintered. They are crumbly as if made of a powder that has been only weakly bonded (e.g. exposed to great pressure but not heated to the point where the particles actually fuse together).Source:eBay seller nebulousstarsContributor:Theodore GrayAcquired:1 September, 2004Price: $12Size: 1"Purity: 99%

Crystal bar.
This completes my set of titanium, zirconium, and hafnium crystal bars (a complete column). All three of these metals are, or used to be, refined using a similar iodic decomposition process, so all can be found in roughly this crystal form. Although I have many favorite samples, the combination of these three crystal bar samples is without doubt my favorite column in the table.

I chose this sample to represent its element in my Photographic Periodic Table Poster. The sample photograph includes text exactly as it appears in the poster, which you are encouraged to buy a copy of.

Etched button 1.
This is an ultra high purity vacuum e-beam melted zirconium button that has had its surface etched with acid to reveal the crystal structure. Kindly donated by Philip Kapchenko of Kaistar R&D, who was disappointed when I guessed right the first time what metal it was. You might think I'm good at guessing elements, but actually it was just luck: Those transition metals are really hard to tell apart without measuring the density.Source:Kaistar R&DContributor:Kaistar R&DAcquired:29 October, 2004Price: DonatedSize: 1"Purity: >99.99%

Etched button 2.
This is an ultra high purity vacuum e-beam melted zirconium button that has had its surface etched with acid to reveal the crystal structure. At least, I think it's zirconium: Philip Kapchenko of Kaistar R&D, who sent me the zirconium button described above, only remembers having sent one button in that package, but there were two when I opened it. They look and feel very similar, so I'm assuming this one is also zirconium, but it's possible it's actually something like niobium instead. Or, maybe it's the other way around and this one is zirconium and the one above is niobium.Source:Kaistar R&DContributor:Kaistar R&DAcquired:29 October, 2004Price: DonatedSize: 1"Purity: >99.99%

Pen.
Is this pen really made of zirconium? The only evidence in favor of this idea is that it's sold in the novelty shop of a major refiner of zirconium metal for industrial and nuclear applications. If anyone should be trusted when they say a pen is a zirconium pen, it would be Wah Chang. Still, it seems a bit hard to imagine, not to mention quite pointless. I can't imagine why it would make sense to construct a pen out of a metal as expensive and difficult to work with as zirconium, especially since none of its unique properties give it particular advantages in the pen arena.
I'm going to have to go with my best guess, which is no zirconium in this pen.Source:Wah ChangContributor:Theodore GrayAcquired:10 January, 2005Price: $46Size: 7"Purity: 0%

Lump.
Strange, partially melted zirconium lump. Perhaps sintered from a powder then mechanically worked? I'm not sure why someone would do that to zirconium, and I have not seen it in this form before. This sample came from an old collection assembled by Ron Hipschman, an old hand at the Exploratorium in San Francisco (my favorite science museum).Source:Ethan CurrensContributor:Ethan CurrensAcquired:23 December, 2005Text Updated:19 November, 2007Price: DonatedSize: 1"Purity: 99.9%

Element coin.
Dave Hamric sells element samples under the name Metallium. He's developed a line of coins struck out of various common and uncommon metals: They are quite lovely, and very reasonably priced, considering the difficulty of creating some of them.
Here is the back side of this coin (click either picture to see it larger):
Click the Sample Group link below to see many other coins made of various elements, or click the link to his website above if you want to buy one like this.Source:Dave HamricContributor:Theodore GrayAcquired:1 December, 2006Text Updated:14 January, 2007Price: $16Size: 0.75"Purity: >99%Sample Group:Coins

Etched crystal rod.
This is one of three short zirconium rods that Ethan Currens etched in a mixture of acids. He used various different combinations of aqua regia, nitric acid, and concentrated hydrofluoric acid to reveal different aspects of the crystal surfaces of these three pieces. All were cut from the same original bar, yet they look surprisingly different as a result simply of different types of etching.Source:Ethan CurrensContributor:Ethan CurrensAcquired:15 March, 2007Text Updated:19 November, 2007Price: DonatedSize: 1"Purity: 99.99%

Etched crystal rod.
This is one of three short zirconium rods that Ethan Currens etched in a mixture of acids. He used various different combinations of aqua regia, nitric acid, and concentrated hydrofluoric acid to reveal different aspects of the crystal surfaces of these three pieces. All were cut from the same original bar, yet they look surprisingly different as a result simply of different types of etching.
This one was just a loan, so it's been returned to Ethan now.Source:Ethan CurrensContributor:Ethan CurrensAcquired:15 March, 2007Text Updated:19 November, 2007Price: DonatedSize: 1"Purity: 99.99%

Etched crystal rod.
This is one of three short zirconium rods that Ethan Currens etched in a mixture of acids. He used various different combinations of aqua regia, nitric acid, and concentrated hydrofluoric acid to reveal different aspects of the crystal surfaces of these three pieces. All were cut from the same original bar, yet they look surprisingly different as a result simply of different types of etching.
This one was just a loan, so it's been returned to Ethan now.Source:Ethan CurrensContributor:Ethan CurrensAcquired:15 March, 2007Text Updated:19 November, 2007Price: DonatedSize: 1"Purity: 99.99%

Flash bulb wool.
I have a magnesium including magnesium-based flash powder and magnesium ribbon used to expose photographic plates.
Bulbs like the one this wire came from were ubiquitous for decades, used by amateur and professional photographers alike. These days it's hard to imagine a world where taking a photograph actually cost money and used up physical supplies like film and flash bulbs.Source:Juan JimenezContributor:Juan JimenezAcquired:6 April, 2007Text Updated:19 May, 2007Price: DonatedSize: 1"Purity: >90%

Corrosion test token.
Tokens like this are made by companies that sell zirconium (and other metal) components for chemical reactors, piping, and the like. The idea is that you hang the token in the chemicals you plan to use, and see how it does before ordering the whole setup.Source: eBayContributor:Theodore GrayAcquired:19 November, 2007Text Updated:19 November, 2007Price: $10Size: 1"Purity: 99.99%

25ml zirconium crucible.
This is a brand new 25ml (little under one fluid ounce) solid zirconium laboratory crucible. While more expensive than common stainless steel or ceramic crucibles, these are a whole lot cheaper than the next grade up, platinum. The goal of a crucible is to withstand high temperatures and corrosive contents without adding any contamination to the material being heated. In this regard zirconium is quite good, but of course not as good as platinum (otherwise why would they ever use platinum at 50 times the price?).Source:eBay seller nw_stuff_sellerContributor:Theodore GrayAcquired:2 December, 2007Text Updated:2 December, 2007Price: $20Size: 2"Purity: 99.9%

Weird lump.
This is an irregular lump of zirconium, probably arc-melted: The seller described it as being a side effect of attempting to alloy zirconium with scandium, so I'm assuming it's not very high purity.Source:eBay seller chregasanaContributor:Theodore GrayAcquired:23 December, 2007Text Updated:23 December, 2007Price: $10Size: 1"Purity: 99%

Giant flash bulb.
This is a huge zirconium wool flash bulb. It's as big as a regular household incandescent bulb, which is much bigger than any flash bulb I've seen. Must have been pretty darn bright. Not to mention expensive in its day, when you consider that each one could only be used once. Imaging that: It used to actually cost money each time you took a photo! Money for film, money for developing the film, and if you needed flash, more money for each flash. Now we take 720 photographs of every sample (a complete circle in 1/2 degree increments), each of those photos is higher quality than an old 35mm film photo, and it doesn't cost a penny more for each one, beyond wear and tear on the camera and a bit of electricity.Source:eBay seller naomimageContributor:Theodore GrayAcquired:19 November, 2008Text Updated:20 November, 2008Price: $1Size: 5"Purity: 99%